Various types of production line systems are known; usually, the production line systems include a linear transport system to move work pieces on transport plates. The transport plates are moved either by conveyor belts, roller conveyors or the like to various work stations. The work stations may be manually operated, that is, may use human operators, for example for assembly or other work; the work stations may, however, also include automatic operating stations, automatic assembly, or connecting stations, stations which are located opposite robots, or similar arrangements. The particular nature of the production line, and the specific working on the work pieces does not form part of the present invention.
The transport plates which carry the work pieces may be movable along the production line in a plurality of horizontal directions. Customarily, the work pieces are movable first along a linear path, then along a path at right angles thereto, and then, again, for example in a linear path. The system may, for example, be generally U-shaped or may be a closed ring system, in which work pieces are mounted on the transport plates at a specific location at the ring system, and worked-on or assembled work pieces removed immediately adjacent thereto, to free the transport plates which are being recycled. The horizontal movement of the transport plates--in whatever selected direction--should be independent of the cadence or time taken to carry out the required work at the respective work stations. Consequently, it may occur in such transport systems that the transport plates, during their transport from one work station to the next may back up and impinge against each other, that is, be immediately adjacent each other. The movement of the transport plates, then, will be in steps, and jolts will be caused; the transport belts or rollers or other transport systems continue to move, which causes wear on the transport or conveyor system, the transport plates, and additionally introduces noise and shock: